A method is described for determining a position of a single-track vehicle. A device for carrying out the method is also described.
To determine the position of a vehicle, the use of a satellite-based positioning system, such as the Global Positioning System (GPS), is known. A precondition for correct functioning of determining the position by way of a satellite-based positioning system is that adequate communication with corresponding satellites is possible. However, in various situations, for example when traveling in a tunnel, in deep road cuttings and/or in parking garages this is only possible with limitations or not at all.
The term “dead reckoning” is taken to mean the process of estimating a momentary position based on a previously determined position and moving this position forward on the basis of a series of measured parameters. These parameters can include, for example, the speed, acceleration and/or the yaw rate of a vehicle, which are measured by use of one or more vehicle sensors. DE 10 2010 031 351 A1 describes such a vehicle sensor.
A drawback of the methods known in the prior art of determining a position of a vehicle is that the known methods are only inadequately suited for use with single-track vehicles which, when traveling through curves, incline towards the inside of the curve. When the vehicle sensors described in the prior art are used in single track vehicles, the inclined orientation-dependent yaw rate, i.e. the yaw rate measured in the vertical axis of the single-track vehicle, is measured. However, in the case of the known methods, dead-reckoning algorithms known from the private car sector cannot be used for single-track vehicles.
It is therefore an object of the invention to provide a method of determining a position by which, in the case of single-track vehicles, it is possible to continue navigating in the event of failure of the GPS signal. A further object of the invention is to provide a device for implementing the method.
These and other objects are achieved through a method and a device according to embodiments of the invention.
According to one form of embodiment, in a method of determining a position of a single-track vehicle, an inclined position of the single-track vehicle and a speed of the single-track vehicle are determined. Preferably, the inclined orientation and/or the speed of the single-track vehicle is/are measured by way of one or more sensors. The speed of the single-track vehicle can, for example, be measured by way of a wheel rotation sensor. To measure the inclined orientation of the single-track vehicle, a device for determining an inclined orientation angle can be used, for example. With regard to this, reference is made to unexamined and published patent application DE 10 2006 057 667 A1, the content of which, particularly in relation to the device described therein for determining an inclined orientation angle in the case of a single-track vehicle, is incorporated by reference herein.
When traveling through curves, the single-track vehicle has a vehicle path yaw rate and a yaw rate dependent on the inclined orientation which differs from the vehicle path yaw rate. The inclined orientation-dependent yaw rate depends on the current inclined orientation of the single-track vehicle, i.e. the inclination angle of the single-track vehicle, and is measured in the direction of the vertical vehicle axis of the single-track vehicle. To measure the inclined orientation-dependent yaw rate of the single-track vehicle, in the described method a yaw rate sensor, such as a gyrometer can be used for example.
From the measured inclined orientation and the measured speed, the vehicle path yaw rate of the single track vehicle is determined. The vehicle path yaw rate is often the yaw rate perpendicular to the surface of the roadway simply designated with the term “yaw rate” and can here and in the following also be called the path angle speed. The vehicle path yaw rate co, can in particular be determined via the following equation:ωz=(sin(φ)·g)/(v·cos(φ)),where φ is the inclination angle or the inclined orientation of the single-track vehicle, v the speed of the single-track vehicle and g the ground acceleration.
By way of the method described here the navigation of a single-track vehicle is advantageously made possible in the event of a short-term failure of the GPS signal. In addition to the navigation of a single-track vehicle this is also particularly of relevance in connection with the breaking off of emergency calls (known as “E-call”).
In accordance with a further form of embodiment, in order to determine the position of the single-track vehicle, a dead-reckoning algorithm is used which employs the vehicle path yaw rate for calculating the position of the single-track vehicle. Advantageously, through the determined vehicle path yaw rate of the single-track vehicle, dead-reckoning algorithms known from the private car sector can be used for dead reckoning in the case of the single track vehicle.
In addition, a device for implementing the method described here is set out. The device can have one or more features of the forms of embodiment already cited in connection with the method.
For example, the device can comprise one or more vehicle sensors, such as a wheel rotation sensor, gyrometer, inclination sensor etc. Furthermore, the device can comprise a calculation unit, such as a computer having a processor and associated memory, to execute a programmed method for determining the vehicle path yaw rate of the single-track vehicle on the basis of the variables determined by way of the vehicle sensor(s), in particular the inclined orientation and the speed of the single-track vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.